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iPhone Duo goes on sale Oct 23, 2026. Developers are likely to update their apps then, so statuses are for reference until launch.

Release day, your time15:57:15

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4399游戏盒-掌上游戏论坛

四三九九网络股份有限公司Social

View in the App Store
On iPhone Duo

Letterboxed

4399游戏盒-掌上游戏论坛 runs in an iPhone-sized window with black bars.

Its latest version is built with the iOS 26.4 SDK,[1] which Apple shows letterboxed on the inner display.[2]

How we know
From the app’s build
Checked on
Version 4.7.0
Build
iOS 26.4 SDK
Latest version
4.7.0, Aug 7, 2026
Status updated

What owners report

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Version history

  1. Version 4.7.0Letterboxed

    iOS 26.4 SDK

    Checked Oct 22, 2026

Sources

  1. App Store build, version 4.7.0

    Built with the iOS 26.4 SDK. Uses none of Apple’s iPhone Duo APIs.

  2. Apple Developer: Prepare your app for iPhone Duo
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